Aanesthetic Agents for Day Surgery - NIHR Health Technology ...

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Results of the adult economic evaluation
TABLE 30 Overnight admissions in the adult study
Procedure, No. of patients No. of
gender in surgical overnight stays
group (% of group)
Adult study 1063 94 (8.8%)
Gynaecology (St. Mary’s) 103 14 (13.6%)
Gynaecology (Wirral) 581 29 (5.0%)
General, male 185 33 (17.8%)
General, female 77 10 (13.0%)
Orthopaedic, male 86 5 (5.8%)
Orthopaedic, female 31 3 (9.7%)
CVs given by adults for induction, by randomisation
group, are summarised in Table 32. The
mean CVs were higher for intravenous induction
than for inhalational induction for all randomisation
arms, indicating a higher magnitude of
preference for intravenous induction among those
who preferred it. Those patients who had received
inhalational induction, but wanted intravenous
induction next time, exhibited smaller CV values
than those who had received intravenous
induction.
The CVs for induction were compared between
those patients who received propofol induction
and those who received sevoflurane induction.
Where intravenous induction was the preferred
400
350
300
250
200
150
100
50
0
No. of patients
option, those patients who received propofol
induction in the study did not give significantly
higher CVs than those who received sevoflurane
induction (p = 0.10). Where inhalational induction
was the preferred option, those patients who
received propofol induction in the study did not
give significantly different CVs than those who
received sevoflurane induction, although there was
a tendency for the CVs to be lower (p = 0.085).
Figure 5 shows the distribution of CVs for
induction. It is clear that there is a scale effect
for scenario A (intravenous), but not for scenario
B (inhalational), which was not evident in the
piloting work. Many patients’ responses appear to
have been constrained by the scale (£0 to £250),
despite pilot work and the option to provide a
value beyond the limits of the scale. This suggests
that the more recent the experience of anaesthesia,
the stronger the preferences expressed.
It also suggests that the CVs reported here are
conservative rather than extravagant values.
Patient preferences for maintenance
of anaesthesia
A total of 907 patients were asked for a preference
for a reduced risk of PONV (scenario C, PONV
risk 7/10; scenario D, PONV risk 3/10) (Table 33).
The results show that 97% patients would choose
the scenario where the risk of PONV was reduced.
The patients who picked scenario C were con-
5 10 15 20 25 30 35 40 45 50 55 60 65
Variable cost (£)
FIGURE 3 Distribution of the variable costs of patients in the adult study